// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2017-2019 The WaykiChain Developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "hash.h"

inline uint32_t ROTL32(uint32_t x, int8_t r) { return (x << r) | (x >> (32 - r)); }

uint32_t MurmurHash3(uint32_t nHashSeed, const vector<uint8_t> &vDataToHash) {
    // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
    uint32_t h1       = nHashSeed;
    const uint32_t c1 = 0xcc9e2d51;
    const uint32_t c2 = 0x1b873593;

    const int32_t nblocks = vDataToHash.size() / 4;

    //----------
    // body
    const uint32_t *blocks = (const uint32_t *)(&vDataToHash[0] + nblocks * 4);

    for (int32_t i = -nblocks; i; i++) {
        uint32_t k1 = blocks[i];

        k1 *= c1;
        k1 = ROTL32(k1, 15);
        k1 *= c2;

        h1 ^= k1;
        h1 = ROTL32(h1, 13);
        h1 = h1 * 5 + 0xe6546b64;
    }

    //----------
    // tail
    const uint8_t *tail = (const uint8_t *)(&vDataToHash[0] + nblocks * 4);

    uint32_t k1 = 0;

    switch (vDataToHash.size() & 3) {
        case 3:
            k1 ^= tail[2] << 16;  // Falls through
        case 2:
            k1 ^= tail[1] << 8;  // Falls through
        case 1:
            k1 ^= tail[0];
            k1 *= c1;
            k1 = ROTL32(k1, 15);
            k1 *= c2;
            h1 ^= k1;
    }

    //----------
    // finalization
    h1 ^= vDataToHash.size();
    h1 ^= h1 >> 16;
    h1 *= 0x85ebca6b;
    h1 ^= h1 >> 13;
    h1 *= 0xc2b2ae35;
    h1 ^= h1 >> 16;

    return h1;
}

int32_t HMAC_SHA512_Init(HMAC_SHA512_CTX *pctx, const void *pkey, size_t len) {
    uint8_t key[128];
    if (len <= 128) {
        memcpy(key, pkey, len);
        memset(key + len, 0, 128 - len);
    } else {
        SHA512_CTX ctxKey;
        SHA512_Init(&ctxKey);
        SHA512_Update(&ctxKey, pkey, len);
        SHA512_Final(key, &ctxKey);
        memset(key + 64, 0, 64);
    }

    for (int32_t n = 0; n < 128; n++) key[n] ^= 0x5c;
    SHA512_Init(&pctx->ctxOuter);
    SHA512_Update(&pctx->ctxOuter, key, 128);

    for (int32_t n = 0; n < 128; n++) key[n] ^= 0x5c ^ 0x36;
    SHA512_Init(&pctx->ctxInner);
    return SHA512_Update(&pctx->ctxInner, key, 128);
}

int32_t HMAC_SHA512_Update(HMAC_SHA512_CTX *pctx, const void *pdata, size_t len) {
    return SHA512_Update(&pctx->ctxInner, pdata, len);
}

int32_t HMAC_SHA512_Final(uint8_t *pmd, HMAC_SHA512_CTX *pctx) {
    uint8_t buf[64];
    SHA512_Final(buf, &pctx->ctxInner);
    SHA512_Update(&pctx->ctxOuter, buf, 64);
    return SHA512_Final(pmd, &pctx->ctxOuter);
}
